Approach to procainamide infusion in adults

VT: ventricular tachycardia; AVRT: atrioventricular reentrant tachycardia; IV: intravenous; QTc interval: corrected QT interval; NAPA: N-acetylprocainamide.

* Some sources describe a maximum dose of 17 mg/kg^[1]. Higher infusion rates are more likely to cause hypotension. Refer to Lexicomp for specific dose adjustments for older patients and those with kidney or liver dysfunction.

¶ Maintenance infusion of procainamide is associated with toxicity (eg, QRS and QTc interval prolongation, torsades de pointes in susceptible patients); seek alternative agents for maintenance of sinus rhythm. If procainamide is selected for ongoing treatment, may administer at 1 to 4 mg/min. Some experts use higher infusion rates (eg, 6 to 10 mg/min). If infusion of procainamide extends beyond 12 to 24 hours, measure QRS duration, QTc interval, and procainamide levels twice daily. Signs of toxicity include QRS prolongation of more than 50% compared with QRS in sinus rhythm at the onset of therapy or a QTc interval greater than normal sex-specific values. Procainamide toxicity may begin at levels >9 mcg/mL but varies considerably between patients. Some experts also measure NAPA levels, but toxic and therapeutic levels are not well-defined.

Δ Alternative agents and approaches available for management depend on the specific tachycardia. For details, refer to UpToDate content on specific arrhythmias (eg, AVRT, preexcited atrial fibrillation, wide-complex tachycardia).